@@ -829,9 +829,6 @@ struct exec
#define ZMAGIC 0413
#define QMAGIC 0314
-/* max code+data+bss space allocated to elf interpreter */
-#define INTERP_MAP_SIZE (32 * 1024 * 1024)
-
/* max code+data+bss+brk space allocated to ET_DYN executables */
#define ET_DYN_MAP_SIZE (128 * 1024 * 1024)
@@ -920,6 +917,7 @@ static inline void bswap_sym(struct elf_sym *sym) { }
#ifdef USE_ELF_CORE_DUMP
static int elf_core_dump(int, const CPUState *);
#endif /* USE_ELF_CORE_DUMP */
+static void load_symbols(struct elfhdr *hdr, int fd, abi_ulong load_bias);
/*
* 'copy_elf_strings()' copies argument/envelope strings from user
@@ -1145,15 +1143,11 @@ static abi_ulong load_elf_interp(struct elfhdr * interp_elf_ex,
char bprm_buf[BPRM_BUF_SIZE])
{
struct elf_phdr *elf_phdata = NULL;
- struct elf_phdr *eppnt;
- abi_ulong load_addr = 0;
- int load_addr_set = 0;
+ abi_ulong load_addr, load_bias, loaddr, hiaddr;
int retval;
abi_ulong error;
int i;
- error = 0;
-
bswap_ehdr(interp_elf_ex);
/* First of all, some simple consistency checks */
if ((interp_elf_ex->e_type != ET_EXEC &&
@@ -1162,7 +1156,6 @@ static abi_ulong load_elf_interp(struct elfhdr * interp_elf_ex,
return ~((abi_ulong)0UL);
}
-
/* Now read in all of the header information */
if (sizeof(struct elf_phdr) * interp_elf_ex->e_phnum > TARGET_PAGE_SIZE)
@@ -1195,41 +1188,56 @@ static abi_ulong load_elf_interp(struct elfhdr * interp_elf_ex,
}
bswap_phdr(elf_phdata, interp_elf_ex->e_phnum);
+ /* Find the maximum size of the image and allocate an appropriate
+ amount of memory to handle that. */
+ loaddr = -1, hiaddr = 0;
+ for (i = 0; i < interp_elf_ex->e_phnum; ++i) {
+ if (elf_phdata[i].p_type == PT_LOAD) {
+ abi_ulong a = elf_phdata[i].p_vaddr;
+ if (a < loaddr) {
+ loaddr = a;
+ }
+ a += elf_phdata[i].p_memsz;
+ if (a > hiaddr) {
+ hiaddr = a;
+ }
+ }
+ }
+
+ load_addr = loaddr;
if (interp_elf_ex->e_type == ET_DYN) {
- /* in order to avoid hardcoding the interpreter load
- address in qemu, we allocate a big enough memory zone */
- error = target_mmap(0, INTERP_MAP_SIZE,
- PROT_NONE, MAP_PRIVATE | MAP_ANON,
- -1, 0);
- if (error == -1) {
+ /* The image indicates that it can be loaded anywhere. Find a
+ location that can hold the memory space required. If the
+ image is pre-linked, LOADDR will be non-zero. Since we do
+ not supply MAP_FIXED here we'll use that address if and
+ only if it remains available. */
+ load_addr = target_mmap(loaddr, hiaddr - loaddr, PROT_NONE,
+ MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
+ -1, 0);
+ if (load_addr == -1) {
perror("mmap");
exit(-1);
}
- load_addr = error;
- load_addr_set = 1;
}
+ load_bias = load_addr - loaddr;
- eppnt = elf_phdata;
- for(i=0; i<interp_elf_ex->e_phnum; i++, eppnt++)
+ for (i = 0; i < interp_elf_ex->e_phnum; i++) {
+ struct elf_phdr *eppnt = elf_phdata + i;
if (eppnt->p_type == PT_LOAD) {
- int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
+ abi_ulong vaddr, vaddr_po, vaddr_ps, vaddr_ef, vaddr_em;
int elf_prot = 0;
- abi_ulong vaddr = 0;
if (eppnt->p_flags & PF_R) elf_prot = PROT_READ;
if (eppnt->p_flags & PF_W) elf_prot |= PROT_WRITE;
if (eppnt->p_flags & PF_X) elf_prot |= PROT_EXEC;
- if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) {
- elf_type |= MAP_FIXED;
- vaddr = eppnt->p_vaddr;
- }
- error = target_mmap(load_addr+TARGET_ELF_PAGESTART(vaddr),
- eppnt->p_filesz + TARGET_ELF_PAGEOFFSET(eppnt->p_vaddr),
- elf_prot,
- elf_type,
- interpreter_fd,
- eppnt->p_offset - TARGET_ELF_PAGEOFFSET(eppnt->p_vaddr));
+ vaddr = load_bias + eppnt->p_vaddr;
+ vaddr_po = TARGET_ELF_PAGEOFFSET(vaddr);
+ vaddr_ps = TARGET_ELF_PAGESTART(vaddr);
+
+ error = target_mmap(vaddr_ps, eppnt->p_filesz + vaddr_po,
+ elf_prot, MAP_PRIVATE | MAP_FIXED,
+ interpreter_fd, eppnt->p_offset - vaddr_po);
if (error == -1) {
/* Real error */
close(interpreter_fd);
@@ -1237,26 +1245,25 @@ static abi_ulong load_elf_interp(struct elfhdr * interp_elf_ex,
return ~((abi_ulong)0UL);
}
- if (!load_addr_set && interp_elf_ex->e_type == ET_DYN) {
- load_addr = error;
- load_addr_set = 1;
- }
+ vaddr_ef = vaddr + eppnt->p_filesz;
+ vaddr_em = vaddr + eppnt->p_memsz;
/* If the load segment requests extra zeros (e.g. bss), map it. */
- if (eppnt->p_filesz < eppnt->p_memsz) {
- abi_ulong base = load_addr + eppnt->p_vaddr;
- zero_bss(base + eppnt->p_filesz,
- base + eppnt->p_memsz, elf_prot);
+ if (vaddr_ef < vaddr_em) {
+ zero_bss(vaddr_ef, vaddr_em, elf_prot);
}
}
+ }
- /* Now use mmap to map the library into memory. */
+ if (qemu_log_enabled()) {
+ load_symbols(interp_elf_ex, interpreter_fd, load_bias);
+ }
close(interpreter_fd);
free(elf_phdata);
*interp_load_addr = load_addr;
- return ((abi_ulong) interp_elf_ex->e_entry) + load_addr;
+ return ((abi_ulong) interp_elf_ex->e_entry) + load_bias;
}
static int symfind(const void *s0, const void *s1)
@@ -1305,82 +1312,87 @@ static int symcmp(const void *s0, const void *s1)
}
/* Best attempt to load symbols from this ELF object. */
-static void load_symbols(struct elfhdr *hdr, int fd)
+static void load_symbols(struct elfhdr *hdr, int fd, abi_ulong load_bias)
{
- unsigned int i, nsyms;
- struct elf_shdr sechdr, symtab, strtab;
+ int i, shnum, nsyms, sym_idx = 0, str_idx = 0;
+ struct elf_shdr *shdr;
char *strings;
struct syminfo *s;
struct elf_sym *syms;
- lseek(fd, hdr->e_shoff, SEEK_SET);
- for (i = 0; i < hdr->e_shnum; i++) {
- if (read(fd, &sechdr, sizeof(sechdr)) != sizeof(sechdr))
- return;
- bswap_shdr(&sechdr, 1);
- if (sechdr.sh_type == SHT_SYMTAB) {
- symtab = sechdr;
- lseek(fd, hdr->e_shoff
- + sizeof(sechdr) * sechdr.sh_link, SEEK_SET);
- if (read(fd, &strtab, sizeof(strtab))
- != sizeof(strtab))
- return;
- bswap_shdr(&strtab, 1);
+ shnum = hdr->e_shnum;
+ i = shnum * sizeof(struct elf_shdr);
+ shdr = (struct elf_shdr *)alloca(i);
+ if (pread(fd, shdr, i, hdr->e_shoff) != i) {
+ return;
+ }
+
+ bswap_shdr(shdr, shnum);
+ for (i = 0; i < shnum; ++i) {
+ if (shdr[i].sh_type == SHT_SYMTAB) {
+ sym_idx = i;
+ str_idx = shdr[i].sh_link;
goto found;
}
}
- return; /* Shouldn't happen... */
+
+ /* There will be no symbol table if the file was stripped. */
+ return;
found:
- /* Now know where the strtab and symtab are. Snarf them. */
+ /* Now know where the strtab and symtab are. Snarf them. */
s = malloc(sizeof(*s));
- syms = malloc(symtab.sh_size);
- if (!syms)
- return;
- s->disas_strtab = strings = malloc(strtab.sh_size);
- if (!s->disas_strtab)
+ if (!s) {
return;
+ }
- lseek(fd, symtab.sh_offset, SEEK_SET);
- if (read(fd, syms, symtab.sh_size) != symtab.sh_size)
+ i = shdr[str_idx].sh_size;
+ s->disas_strtab = strings = malloc(i);
+ if (!strings || pread(fd, strings, i, shdr[str_idx].sh_offset) != i) {
+ free(s);
+ free(strings);
return;
+ }
- nsyms = symtab.sh_size / sizeof(struct elf_sym);
+ i = shdr[sym_idx].sh_size;
+ syms = malloc(i);
+ if (!syms || pread(fd, syms, i, shdr[sym_idx].sh_offset) != i) {
+ free(s);
+ free(strings);
+ free(syms);
+ return;
+ }
- i = 0;
- while (i < nsyms) {
+ nsyms = i / sizeof(struct elf_sym);
+ for (i = 0; i < nsyms; ) {
bswap_sym(syms + i);
- // Throw away entries which we do not need.
- if (syms[i].st_shndx == SHN_UNDEF ||
- syms[i].st_shndx >= SHN_LORESERVE ||
- ELF_ST_TYPE(syms[i].st_info) != STT_FUNC) {
- nsyms--;
- if (i < nsyms) {
+ /* Throw away entries which we do not need. */
+ if (syms[i].st_shndx == SHN_UNDEF
+ || syms[i].st_shndx >= SHN_LORESERVE
+ || ELF_ST_TYPE(syms[i].st_info) != STT_FUNC) {
+ if (i < --nsyms) {
syms[i] = syms[nsyms];
}
- continue;
- }
+ } else {
#if defined(TARGET_ARM) || defined (TARGET_MIPS)
- /* The bottom address bit marks a Thumb or MIPS16 symbol. */
- syms[i].st_value &= ~(target_ulong)1;
+ /* The bottom address bit marks a Thumb or MIPS16 symbol. */
+ syms[i].st_value &= ~(target_ulong)1;
#endif
- i++;
+ syms[i].st_value += load_bias;
+ i++;
+ }
}
- syms = realloc(syms, nsyms * sizeof(*syms));
+ syms = realloc(syms, nsyms * sizeof(*syms));
qsort(syms, nsyms, sizeof(*syms), symcmp);
- lseek(fd, strtab.sh_offset, SEEK_SET);
- if (read(fd, strings, strtab.sh_size) != strtab.sh_size)
- return;
s->disas_num_syms = nsyms;
#if ELF_CLASS == ELFCLASS32
s->disas_symtab.elf32 = syms;
- s->lookup_symbol = lookup_symbolxx;
#else
s->disas_symtab.elf64 = syms;
- s->lookup_symbol = lookup_symbolxx;
#endif
+ s->lookup_symbol = lookup_symbolxx;
s->next = syminfos;
syminfos = s;
}
@@ -1727,8 +1739,9 @@ int load_elf_binary(struct linux_binprm * bprm, struct target_pt_regs * regs,
free(elf_phdata);
- if (qemu_log_enabled())
- load_symbols(&elf_ex, bprm->fd);
+ if (qemu_log_enabled()) {
+ load_symbols(&elf_ex, bprm->fd, load_bias);
+ }
if (interpreter_type != INTERPRETER_AOUT) close(bprm->fd);
info->personality = (ibcs2_interpreter ? PER_SVR4 : PER_LINUX);
First, adjust load_symbols to accept a load_bias parameter. At the same time, read the entire section header table in one go, use pread instead f lseek+read for the symbol and string tables, and properly free allocated structures on error exit paths. Second, adjust load_elf_interp to compute load_bias. This requires finding out the built-in load addresses. Which allows us to honor a pre-linked interpreter image when possible, and eliminate the hard-coded INTERP_MAP_SIZE value. Signed-off-by: Richard Henderson <rth@twiddle.net> --- linux-user/elfload.c | 189 +++++++++++++++++++++++++++----------------------- 1 files changed, 101 insertions(+), 88 deletions(-)